A video preview of the sitdown shows the Republican politician (and potential presidential contender) explaining that he secretly underwent the procedure in February (after consulting with weight-loss surgery specialist Dr. George Fielding) because he wanted to be healthy for his wife, Mary Pat, and their four children.

"Last fall, I was turning 50 and it really was a moment of reflection for me," Christie says. "And so I really just felt like for Mary Pat and for the kids that I needed to take a more significant step to try to get my weight under control so that I could have a really active next half of my life."

Christie, who mocked his size by eating a donut on The Late Show With David Letterman two weeks before surgery, added: "The biggest thing about it for me has been I’m just not very hungry anymore and that’s a huge change for me."